SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7994b315b034a18d8e1f39d1abab6bc43dba672c65bef0c6795e76920c7ab116' 
  AND token = 'SEHociUGzX5T1SlJNXdavs7m6kxUeoJ6Rh9MwY0jxqw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}